Apparatus for making metal tubes



Oct. 24, 1939. J. H. WRIGHT APPARATUS FOR MAKING METAL TUBES Filed Nov. 15 1938 4 Sheets- Sheet l INVENTOR A JoH/v HARRY WEIGHT 5 WA ATTORNEYS mm mm mm E R Oct. 24, 1939. J, H, WRIGHT 2,177,545

APPARATUS FOR MAKING METAL TUBES Filed Nov. 15, 1938 4 Sheets-Sheet 2 Egg. 5.

INVENTOR J HN HARRY ATTORNEYS Oct. 24, 1939. J. H. WRIGHT 2,177,545

APPARATUS FOR MAKING METAL TUBES Filed Nov. 15, 1938 4 Sheets-Sheet 3 Fig, 8. 53

iNVENTOR JoH/v HARRY WRIGHT d ATTORNEYS Oct. 24, 1939. J HT 2,177,545

APPARATUS FOR MAKING METAL TUBES Filed Nov. 15, 1938 I 4 Sheets-Sheet 4 s INVENTQR JOHN HARRY WR/ HT ATTORNEYS Patented Oct. 24, 1 939 1 UNITEDSTATES PATENT OFFICE APPARATUS FOR MAKING METAL TUBES John Harry Wright, Irvington, N. J.

Application November 15, 1938, Serial No. 240,457

3 Claims. (Cl. 153-42) This invention relates to apparatus for and in the body of said spreading means in such a the method of forming sheet metal into hollow manner that the periphery of the wheel engages bodies, or tubes of various sizes and shapes. the edges of the longitudinal scam in order to in- In the past, such tubes were made with seams sure the spreading apart of the longitudinal 5 formed by overlapping and folding the edges of edges of the seam. 5

the sheet metal in order to form a tight seam, or The spreading means merely spreads but does by welding the edges of the seam together, or by not bend the tube in order that the longitudinal means of a swedging apparatus which tapped the edges of the same may snap together, as the tube sides of the tube until the edges of the sheet metal passes from the spreading means.

were brought together. These tubes were expen- Other objects and advantages inherent in the 10 sive to make, both in time and material, and in invention will become apparent as the specificathe case of the tube formed by swedging appation proceeds and when taken in conjunction ratus, did not have a tight seam. with the accompanying drawings.

.An objectof my invention is to provide an im- Figure 1 is a plan view of the apparatus of my proved method of manufacturing a metal tube invention. 15 from sheet metal so as to form a tight seam along Figure 2 is a longitudinal sectional view taken.

said tube in a simple and efiective manner. on the line 22 of Figure 1.

Another object of my invention is to provide Figure 3 is a sectional view on the line 3-3 of apparatus upon which a metal tube may be Figure 1 showing the gauge plates which guide formed from a piece of sheet metal, said tube the sheet metal as it enters the machine. 20 having a tight seam. Figure 3A is a cross-section of the sheet metal A further object of my invention is to provide s it te t e machinean apparatus upon which a metal tube may be Figure 4 is a sectional view on the line 4--4 01 formed from a piece of sheet metal the tube be- Figure 1 Showing the fi Set Of breaking w ing bent into a tube of lesser diameter in such rollers t o Which the Sheet metal P 25 a manner that the longitudinal edges of the after entering t a ne. seam overlap and then spread so that the longi- Figure 4A is a. cross-section of the sheet metal tudinal edges of the seam will snap together as after t passes u h the fi st s t of r n the tube passes from the spreading means by vird wn ro lerstue of the spring created along the side of the F re 5 is a section taken on the line 55 of 30 tube adjacent the seam. Figure 1 showing the second set of breaking down In accomplishing the above objects, it has been Tellers, through w c the Sheet metal P sfound most satisfactory, according to one em- Figure 5A is a cross-section of the sheet metal bodiment of the present invention, to provide after it has passed through the Second set of breaking down rollers and finishing rollers which breaking down rollers. 5

are driven by means of motor to form a flat sheet Figure 6 is a cross-sectional View taken on the of sheet metal into a tube having a longitudinal line 6-6 of Figure 1 showing the finishing rollers. seam, the edges of which are slightly spaced Figure 6A is a cross-section of the sheet metal apart.- after passing through the finishing rollers.

40 A sp ad plate is th n pr vided for raisin Figure 7 is a sectional view taken on the line 40 one edge of said lo ud n S above the l'| of Figure 1 showing a cross-section of means other in order that the same may be fed between for spreading and raising one edge of t sheet overlapping rollers having a space of lesser diammetal f min a m, eter than the tube as it leaves the finishing roll- Figure 7A is a cross sectional View of the tube em in order a the Same be bent into a after passing the means for raising an edge of 45 tube of lesser diameter, having one edge of the the tube enf gfgg l g i gg ggg fig gj g gfz diam. Figure 8 is asectional view taken on the line eter slightly larger than the inside diameter of of Flgure 1 showing h ovelila'ppmg rollers" the finished tube ismounted longitudinally for- Flgure 8A is crossfiechonai of the tube ward of the overlapping rollers. The end adja'' afterpassirlg thwueh saidoveflappmg rollers; cent said overlapping rollers is tapered, the small- 15 a sectlohal View i on the 11118 est diameter or which engages the inside surface f u s w n the fi hm plu of the tube as it passes from the overlapping rollgu e 10 s eross-seetlonal View Of the ers. A wheel having bevelled edges is mounted ished tube after it passes from the finishing plug. 55

sheet metal after it passes through the second set of breaking down rollers.

Figure 14 is a perspective view of the piece of sheet metal after it passes through the finishing rollers.

Figure 15 is a perspective view of the piece of sheet metal after it passes the edge raising means. Figure 16 is a perspective view of the sheet metal after passing through the overlapping rollers.

Figure 17 is a perspective view of the completed tube after passing from the finishing plug.

Figure 18 is a perspective view of the part of the apparatus showing the sheet metal passing therethrough from the time it leaves the last breaking down roller until the completed tube is formed.

Figures 19, 20, 21 and 22 are cross-sectional views of various shaped hollowed bodies which might be formed by the method and apparatus of my invention.

Like numerals refer to like parts throughout the several views.

The apparatus of the present invention consists of a bed plate 25 supported on legs 26. Mounted upon the bed plate 25 are the various supports for the several forming rollers and dies.

The various rollers and dies are mounted longitudinally along the surface of the bed plate 25 so that sheet metal may be fed into one end of the apparatus and is formed into a hollow metal body or a tube as it progresses through the various stages.

At one end of the machine are gauge plates 21- and 28 through which the sheet metal to be formed into a tube is fed. Adjacent the plates are a set of breaking-down rollers 29, shown in cross section in Figure 4, mounted in the supports 30, which rollers form the sheet metal strip so that the same is substantially semi-circular in cross-section as shown in Figure 4A.

The rollers 29 are driven through a gear 3| mounted on the shaft 32 which is further supported by a pillow block 33. Guide plates 34 are mounted on the bed plate 25 to engage the sides of the sheet metal strip as it passes from the breaking-down rollers 29.

Mounted in supports 35 formed integrally with the bed plate 25 are anothef set of breakingdown rollers 36 which are shaped to form the sheet metal strip substantially U-shaped, as shown in Figure 5A, the rollers 36 being shown in cross-section in Figure-7. The breaking-down rollers 36 are driven by means of a gear 31 mounted on the shaft 38 which is supported in the support 39.

An idler gear 49 is supported in the support 4|, said idler gear being positioned to mesh with gears 3| and 31.

Mounted on the bed plate 25 longitudinally forward of the breaking-down rollers 36 is a chuck 42 having a round funnel-shaped passage 43 therethrough, the diameter of the passage being larger'at its opening adjacent the breakingdown rollers 36 the same becoming progressively smaller to the opposite opening. A longitudinal slot 44 is formed in the top of the chuck 42 adjacent the end nearest the breaking-down rollers 36.

Guide rollers 45 and 46 are rotatably mounted on shafts 41 and 48 the axes of which are perpendicular to the axis of the breaking-down rollers. The surface of the rollers 45 and 46 are grooved in order to engage the sides of the partially formed tube as it passes from the chuck 42. The shafts 41 and 48 are mounted in blocks which are slidably mounted on the bed plate 25 in order that the roller may accommodate different sized tubes.

Finishing rollers 49 mounted in supports 50 on the bed plate 25 are positioned longitudinally forward of the guide rollers 45 and 46. The finishing rollers are adapted to form the sheet metal into a tube circular in shape but having an opening 5|, as shown in Figure 6A, extending longitudinally thereof. The finishing rollers 49 are shown in cross-section in Figure 6. The finishing rollers 49 are driven by a gear 52 mounted on the shaft 53 which is mounted in pillow block 53A.

The gear 52 is adapted to enmesh with an idler gear 54 mounted in a pillow block 55, the idler gear 54 in turn being adapted to engage the gear 58. The idler gear 54 is driventhrough a gear 58 mounted below the same on the main drive shaft 58A, which is driven by any suitable motor not shown.

Positioned longitudinally forward of the finishing rollers 49 is a spreading plate 59, one edge'of which is adapted to extend diagonally into the opening 5| .in the metal tube, the spreading plate raising one edge of the metal tube and bending the other edge downwardly as shown in Figures 7 and "7A of the drawings.

The spreading plate 59 is preferably, as shown in the drawings, circularly shaped and is pivotally mounted on a pin 60 which is fastened in a support 6| on the bed plate 25. The plate 59 is substantially thin at the periphery, being'made progressively thick to the center of the same. It is understood, of course, that the spreading plate 59 may be made rectangular or square in shape and mounted diagonally on the guide plate 6| so that an edge of said plate would engage the opening 5| of the tube raising one edge of the tube and lowering the other.

Mounted longitudinally forward of the spreading plate 59 are overlapping rollers 62 which, in turn, are mounted in supports 63 in the bed plate 25. The space 64 formed between the rollers 59 by the grooves about the circumference of said rollers is of lesser diameter than the outside diameter of the tube as it passes from the finishing rollers 49.

The metal passes between the guide plate 6|, which also acts as a support for the spreading plate 59, and the gauge plate 6|A which plates are spaced apart a sufiicient distance to contact either side of the metal tube as it passes from the finishing rollers. The end of the gauge plates 6| and 6|A are tapered toward each other so that the sides of the metal tube passing therethrough will be pressed together in order that the tube will fit into the space 64 between the overlapping roller.

Since one edge of the opening 5| in the tube has been spread above the other edge by the spread-- ing plate 59, the overlapping rollers 62 will bend the sides of the metal tube inwardly one edge of the opening overlapping the other, as shown in cross-section in Figure 8A.

The overlapping rollers 62, therefore, bend the metal into a tube of lesser diameter than the tube formed by the finishing rollers 48, said tube,

however, having one edge of the longitudinal seam overlapping the other.

The overlapping rollers 62 are driven by means of a gear 65 mounted in pillow block 65A, through an idler gear 66 mounted at 61, the gear 66 being, in turn, driven by the gear 52.

Mounted in a manner to engage the inside of the tube as it passes from the overlapping rollers, is a finishing plug 68. The plug 68 has an outside diameter which is slightly larger than the inside diameter of the finished metal tube, the body being tapered on the end 69 nearest the overlapping rollers so the smallest diameter at the end of the plug is slightly less than the inside diameter of the metal tube as it passes from the overlapping rollers 62.

As the metal tube passes from the overlapping rollers 62,.the end of the plug 69 engages the inside of the tube and, as the tube moves over the tapered surface of the plug, the tube is gradually spread until it reaches the desired size.

A wheel III is rotatably mounted in a recess 16A within the body of said plug, a portion of the circumference of the same extending above the surface of the plug 68. The wheel 16 has a bevel about its periphery, one side H thereof being bevelled at a greater angle than the other side 12. A knife-like projection I3 is formed about the circumference of the wheel I0.

The wheel 10 acts as a guide to the metal tube and separates the edges of the metal tube along the seam by means of the projection "and the bevels II and 12. Since the bevel II is at a greater angle than the bevel I2 an edge of the seam is slightly raised in order that one edge of.

the seam may be brought into approximate alignment with the other.

A roller I4 is rotatably mounted in the plug 68 and is adapted to engage the inside diameter ofthe metal tube adjacent the seam in order that both sides of the seam will be in exact alignment.

The plug 68 acts to spread the metal tube after it leaves the overlapping rollers 62 and does not in any way bend the metal, so that the spring action produced in overlapping the tube and then spreading it will tend to snap the edges of the seam together as the tube passes fromthe plug 68. i

The plug 68 is mounted on the apparatus by means of a rod 15 which'is screw threaded and adapted ,to engage the end 69 of the plug. The rod 15 extends longitudinally along the machine and is screw threaded at its opposite end to engage a slotted fitting I6 which is pivotally mounted on a T-shaped fitting TI so that the vertical arm 18 of said fitting extends through the slot. The T-shaped fitting is fastened in the longitudinal slot 44 in the chuck 42.

The rod 15, in this manner, will extend through the central portion of the metal tube being formed and will allow the plug avertical movement in accordance with any up and down movement of the metal tubing.

Difierent shaped hollow metal bodies having a tight seam, as shown in Figures 19 to 22' inclusive, may be formed by the method and apparatus of my invention by merely changing the size and shape of the breaking-down and finishing rollers, and spreading the edges of the seam of such a metal body apart so that the samebay be overlapped and then spread apart by a plug of the desired size and shape so thatspring is created in the metal body which will snap the edges of the seam together as it passes from the plug.

In the operation of the apparatus of my inmg rollers 49 is a spreading plate 59.

vention power is applied to a motor which, in turn, revolves the shaft 58a driving the gear 58 which turns the idler gear 54. The idler gear 54, which is enmeshed with the gear 51 which drives the breaking-down rollers 36, and the gear 52 which drives the finishing rollers 49, is turned in an anti-clockwise direction, which drives the gears 31 and 52 in a clockwise direction. The gear 52 is enmeshed with an idler gear 61 which ,is enmeshed with the gear 65 which drives the overlapping roller 62 in a clockwise direction. The gear 3'! is enmeshed with an idler gear 46, in turn, is enmeshed with the gear 3| so as to drive the breaking-down rollers 29 in a clockwise direction.

After power has been applied to these gears and the rollers are set in motion a piece of sheet metal, which may be of any desired length or may be a continuous strip, is fed into the apparatus through the gauge plates 21 and 28, the

distance between the gauge plates being the same as the width of the sheet metal. The sheet metal may be sheet brass, sheet iron, sheet aluminum, or like sheet metal.

The metal then passes through the breakingdown rollers 29 which shapes the surface of the same semi-circularly longitudinally, as shown in cross-section in Figure 4A and in perspective in Figure 12. Since the breaking-down rollers are driven in a clockwise direction, a forward longitudinal movement is imparted to the sheet metal.

From the breaking-down rollers 29, the metal passes between guide plates 34 which are spaced apart at a distance to engage the sides of the sheet metal passing therethrough. The sheet metal then passes through a second set of breakdown rollers 36 which are formed in a manner to place a greater curve on the longitudinal surface of the sheet metaL'as shown in cross section in Figure A and in perspective in Figure 15. A further forward movement is imparted to the sheet metal by the revolution of the breakingdown rollers 29 in a clockwise direction.

The sheet metal then passes through the funnel-shaped passage 43 in the chuck 42 which forms the sheet metal into a substantially round body.

Upon leaving the chuck 42 the sheet metal passes between guide rollers 65 and 46 which are adjustably mounted on the bed plate 25, so that the recessed surfaces thereof may be brought in contact with the outside circumference of various sized tubes and thereby guide the same. The

sheet metal then passes through the finishing rollers 49 which forms the sheet metal into a circular tube, in the embodiment of the invention, as shown, having a longitudinal seam therein, the edges of the same being spaced apart as shown at 5! in Figure 6A, and as shown in perspective in Figure 14.

After passing through the finishing rollers 49, the edges of the longitudinal seam in the tube are spaced apart and a tight seam is not obtained.

Various means of obtaining a tight seam have been previously tried but I have devised a simple apparatus for obtaining a very tight longitudinal seam in a hollow metallic body form of sheet metal.

Mounted longitudinally forward of the finish- As the sheet metal tube passesfrom the finishing rollers 49, oneedge of the spreading plate 59', which is so mounted as to extend diagonally into the opening 5|, raises one edge of the longitudinal ment to the tube.

The spreading plate 59 revolves in order to decrease friction and wear between the edge of the seam and the spreading plate 59. However, a fixed. plate may extend diagonally into the opening 5| of the seam in a sheet metal tube and serve the same purpose. The shape of the sheet metal tube immediately after it passes through the spreading operation is shown in cross sect-ion in Figure 7A and in perspective in Figare 15.

From the spreading plate 59, the metal tube passes into the overlapping rollers 62. The space 64 between the overlapping rollers is of lesser diameter than the tube as it passes the spreading plate 59.

The gauge plates BI and Gla, since the ends adjacent the overlapping rollers 52 are tapered toward one another press the sides of the metal tube inwardly after the tube passes the spreading plate 59. The tube, therefore, will have a smaller diameter and may be fed into the space 64 between the overlapping rollers62.

One edge of the tube is raised by the spreading plate 59 so that this raised edge will overlap the other edge as the tube passes through the overlapping rollers.

The overlapping rollers bend the metal into a tube of smaller diameter with an overlapped seam.

The overlapping rollers 62 are driven in a clockwise direction which imparts a forward move- Figure 8A shows a cross section of the sheet metal tube after it passes from the overlapping rollers, the tube also being shown in perspective in Figure 16.

From the overlapping rollers 52 the tube is moved onto the tapered end 69 of the finishing plug 68, the outside circumference of said tapered end engaging the inside circumference of the tube. As the tube moves over the tapered end 69 of the plug, the tube is spread apart until the maximum circumference of the. taper is reached. The maximum circumference of the taper is such as to' take the overlap out of the tube. The knife-like projection 13 on the wheel I0 engages the edges of the sheet metal tube along the seam, the bevelled periphery of the wheel further spreading apart the edges of the same. The surface of the roller 15 which extends laterally across the plug 68 engages the inside circumference of the metal tube adjacent the seam, which will bring the edges of the seam level with one another in order that the same" ment through its mounting, as previously de-- scribed, in order that the same may adjust itself automatically to any up and down movement of the tube as it passes through the machine.

Through bending the tube in the overlapping roller 62, so that the same is of lesser diameter than the diameter desiredin the finished tube, and then spreading the same by means of the finishing plug 68, a spring action in the metal of the tubeis created along the back, or the portion diametrically opposite the seam, so that as the tube passes from the plug 68, the body of which is slightly larger in circumference than the inside circumference of the finished tube, the'edges of the same will be snapped together, forming a very tight longitudinal seam.

It will be understood, of course, that by varying the shape of the breaking-down rollers, the finishing rollers, the over-lapping rollers and the plug, different shaped hollow sheet metal bodies may be formed by the-method of my invention,

various shapes being shown in Figures 19 to 22 inclusive.

It is not my intention to limit this invention to the precise construction shown, but rather to cover all equivalent structures as defined by the scope of the following claims.

I claim:

1. In tubeforming apparatus, the combination of means for progressively bending a strip of sheet metal into tubular form having a longitudinal seam therein, means rotatably mounted on said apparatus the periphery of the same being adapted to extend into and raise one edge of said longitudinal seam, laterally v disposed bending rollers having a space of lesser diameter than said tube therebetween through which said sheet metal tube passes'thereby overlapping the edges of said longitudinal seam, spreading means longitudinally disposed having a body of slightly greater diameter than the inside diameter of the metal tube to be formed,.one end of said means being tapered to engage the inside surface of said tube as it passes from said bending rollers, means for mounting said spreading means extending through said tube one end of which is attached to the tapered end of said spreading means and the other end being pivotally fastened to said tube forming apparatus at a point before the tubewis formed, a wheel rotatably mounted in said body having bevelled edges on the opposite sides of the periphery thereof, one of said bevelled edges being formed at a greater angle than the other, said bevelled edges forming a thin projection about the circumference of the wheel in the center of the surface of said periphery, said thin projection and said bevelled edges being adapted to engage and spread apart the opposite edges of said longitudinal seam, and aligning means mounted in said body to align the edges of said seam so that said edges of the longitudinal seam of said tube will spring togather as said tube passes from said spreading means.

2. In tube forming apparatus, the combination of means for progressively-bending a strip of sheet metal into tubular form having a longitudinal seam therein, means rotatably mounted on said apparatus the periphery of the same being adapted to extend into and raise one edge of said longitudinal seam, laterally disposed bending rollers having a space of lesser diameter than said tube therebetween through which said sheet metal tube passes, thereby overlapping the edges of said longitudinal seam, and spreading means longitudinally disposed having a body of slightly greater diameter than the inside diameter of the metal tube to be formed, one end of said means being tapered to engage the inside surface of said tube as it passes from said bending rollers, means for mounting said spreading means extending through said tube one end of which is attached to the tapered end of said spreading means and the other end being pivotally fastened to said tube forming apparatus at a point before the tube is formed, a wheel rotatably mounted in said body having bevelled edges on the opposite sides of the periphery thereof, one of said bevelled edges being formed at a greater angle than the other, said bevelled edges forming a thin projection about the circumference of the .wheel in the center of the surface of said periphery, said thin projection and said bevelled edges being adapted to engage and spread apart the opposite edges of said longitudinal seam.

3. In tube forming apparatus, the combination of means for progressively bending a strip of sheet metal into tubular form having a longitudinal seam therein, means adapted toextend into said longitudinal seam and raise one edge of said seam outwardly and above the other edge, laterally disposed bending rollers having a space of lesser diameter than said tube therebetween through whiclw said sheet metal tube passes, thereby overlapping the edges of. said longitudinal seam, and spreading means longitudinally disposed having a body of slightly greater diameter than the inside diameter of the metal tube to be formed, one end of said means being tapered to engage the inside surface of said tube as it passes from said bending rollers, means for mounting said spreading means extending through said tube one end of which is attached to the tapered end of said spreading means and the other end being pivotally fastened to said tube forming apparatus at a point before the tube is formed, a wheel rotatably mounted in said body having bevelled edges on the opposite sides of the periphery thereof, one of said bevelled edges being formed at a greater angle than the other, said bevelled edges forming a thin projection about the circumference of the wheel in the center of the surface of said periphery, said thin projection and said bevelled edges being adapted to engage and spread apart the opposite edges of said longitudinal seam, and aligning JOHN HARRY WRIGHT. 

